| Criteria | Miscibility | Solubility | Remarks |
| Definition | The ability of two liquids to mix in all proportions, forming a homogeneous solution | The ability of a solute (solid, liquid, or gas) to dissolve in a solvent to form a homogeneous solution | Miscibility refers specifically to liquid–liquid combinations, while solubility can apply to any phase |
| Phase of Components | Involves liquid-liquid systems | Involves solid, liquid, or gas solutes in a liquid solvent | Miscibility is a special case of solubility involving two liquids |
| Extent of Mixing | Either completely miscible (e.g., ethanol and water) or immiscible (e.g., oil and water) | Can be fully, partially, or sparingly soluble depending on solute-solvent interactions | Miscibility is often binary; solubility is measured in concentration units (e.g., g/L, mol/L) |
| Thermodynamic Principles | Governed by intermolecular forces like hydrogen bonding, dipole-dipole, and dispersion forces | Governed by Gibbs free energy, enthalpy, entropy, and solute-solvent interactions | Both depend on similar molecular forces but have different quantitative interpretations |
| Temperature Dependence | May change slightly with temperature (especially for borderline miscible liquids) | Often strongly influenced by temperature | Solubility of most solids increases with temperature, while gases often become less soluble |
| Examples | Water and acetone (miscible); water and hexane (immiscible) | NaCl in water (soluble); AgCl in water (sparingly soluble); CO₂ in water (gas solubility) | Illustrative examples show phase and chemical differences between the two concepts |
| Quantitative Measurement | Generally described qualitatively (miscible, partially miscible, immiscible) | Measured quantitatively as concentration (e.g., mg/mL, Molarity) | Solubility is quantifiable; miscibility often is not except via phase diagrams |
